Rapid Formation and Resolution of Cataracts Following Orthopedic Surgery for a Patient With Charcot-Marie-Tooth Disease FREE

Rapid development and nonsurgical resolution of significant cataracts is extremely rare. Herein, we report an unusual case of bilateral, rapidly developing cataracts following orthopedic surgery for a patient with Charcot-Marie-Tooth disease (CMTD). The cataracts regressed within 45 days of surgery.

A 45-year-old man was referred for a third opinion regarding vision loss. The vision loss began 2 days after a 4-hour, unremarkable foot surgery for a foot deformity due to type 2 CMTD, an autosomal dominant primary axonal neuropathy. The patient's medical history was otherwise unremarkable. Preoperative 7-item basic metabolic panel and complete blood cell count findings were unremarkable. Postoperatively, his blood chemistry was unremarkable except for hypokalemia, with a potassium level of 3.2 mEq/L (to convert to millimoles per liter, multiply by 1.0). Standard operative medications were delivered, including the following: 2 g of cefazolin, 10 mL of ropivacaine hydrochloride, 0.75%, as a right lower extremity block, 5 mg of midazolam, and 100 μg of fentanyl citrate before induction; 60 mg of lidocaine, 200 mg of propofol, and 50 mg of rocuronium bromide during induction; and 2 mg of cefazolin and 4 mg of ondansetron hydrochloride toward the conclusion of the case. The case was without complication. Postoperatively, the patient's pain was controlled with hydromorphone hydrochloride via a patient-controlled analgesia pump. During his hospital stay, he received nasal mupirocin, docusate sodium, and potassium chloride. The patient was discharged on postoperative day 1 with oxycodone hydrochloride and his usual home medications: α-lipoic acid, 400 mg/d; ascorbic acid, 500 mg/d; coenzyme Q10, 600 mg/d; vitamin B complex daily; and a multivitamin. On ophthalmic examination 29 days after surgery, the patient's best-corrected visual acuity was 20/40 OU while wearing contact lenses with the following prescription: −1.00 + 0.25 × 180 OD and −1.25 + 0.50 × 173 OS. Intraocular pressure measured 15 mm Hg OU. Slitlamp examination results were unremarkable except for significant bilateral posterior cortical cataracts and a Mittendorf dot in the left eye (Figure, A and B). Fundus examination, optical coherence tomography, and fluorescein angiography findings were unremarkable. Follow-up was arranged for cataract extraction evaluation. The patient was seen 16 days later in follow-up, and he described resolution of the vision loss after 1 week of self-initiating the use of an eyedrop containing N-acetylcarnosine, 1%, dosed at 2 drops 4 times daily. His best-corrected visual acuity improved to 20/30 OD and 20/25 OS. Examination revealed complete resolution of the cataracts (Figure, C and D).

The mechanism of rapid formation of posterior cortical cataracts following orthopedic surgery for CMTD in this case is unknown. Recent eye examination prior to surgery showed no cataracts. His operative and perioperative medications were not found to be linked to cataract formation by PubMed search. Type 2 CMTD is commonly associated with a connexin gap junction mutation as well as several other mutations. Connexins have long been studied in cataractogenesis and are known to be involved in metabolite, ion, and water transport between lens fibers.¹ There are also reports of cataract formation in dynamin-mutated type 2 CMTD,^1- 2 but there are no reports to our knowledge of a spontaneously regressing cataract as seen in our case. A literature search of the other known genes for type 2 CMTD did not reveal any association with cataracts. Reports of spontaneously resolving cataracts have been noted following intraocular surgery.³ These were thought to arise from several potential mechanisms, one being impaired sodium-potassium adenosine triphosphatase channels with electrolyte imbalance.³ The feathering sutural cataracts noted in these studies are similar to those found in our patient. This finding, along with gap junction and dynamin studies, suggests a brief osmotic imbalance as a potential cause. Other spontaneously resolving cataracts have been previously reported, usually associated with significant metabolic disease or intralenticular trauma. These reports offer suggestions of potential resolving mechanisms involving lens epithelial growth and reestablishment of ionic balance.⁴ The importance of the patient's antioxidant home medications and N-acetylcarnosine eyedrops in his cataract resolution is unknown. As described by Toh et al,⁵ further independent research of clinical effectiveness is still needed to validate research claims of N-acetylcarnosine that have significant conflicts of interest in humans.